Molecular weight tensile strength

Resin Molecular Weight Tensile Strength, MPa °C Improvement Factor Ref. 

Tensile properties of rigid-rod fibers, especially tensile strength, generally depend on molecular weight. With increasing molecular weight, tensile strength and... 

The deterioration influences the physical and chemical properties, such as morphology, molecular weight, tensile strength, elongation at break and colour. 

Tensile elongation of PVA is extremely sensitive to humidity and ranges from < 10% when completely dry to 300—400% at 80% rh. Addition of plasticizer can double these values. Elongation is independent of degree of hydrolysis but proportional to the molecular weight. Teat strength increases with increasing relative humidity or with the addition of small amounts of plasticizer. 

Film or fibers derived from low molecular weight polymer tend to embrittle on immersion ia acetone those based on higher molecular weight polymer (>0.60 dL/g) become opaque, dilated, and elastomeric. When a dilated sample is stretched and dried, it retains orientation and is crystalline, exhibiting enhanced tensile strength. The tensile heat-distortion temperature of the crystalline film is iacreased by about 20°C, and the gas permeabiUty and resistance to solvent attack is iacreased. 

Desirable properties of elastomers include elasticity, abrasion resistance, tensile strength, elongation, modulus, and processibiUty. These properties are related to and dependent on the average molecular weight and mol wt distribution, polymer macro- and microstmcture, branching, gel (cross-linking), and... 

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